Nanofibrous Hyper-Cross-Linked Polymer Based on Veratraldehyde-Derived Triarylimidazole for Cationic Organic Pollutant Adsorption

Lignin, a byproduct of the pulp and paper industry and the second-most abundant biomacromolecule, exhibits distinctive characteristics including an aromatic skeleton, complex structure, and challenges related to its utilization. In this study, a triarylimidazole was synthesized from veratraldehyde, a potential lignin derivative, and employed as a monomer for the preparation of ionic hyper-cross-linked polymers characterized by a fibrous and porous microstructure. The presence of methoxy groups endows the resulting ionic hyper-cross-linked polymers with a chemical structure comprising electron-rich aromatic rings and adjacent imidazolium groups, which facilitate synergistic noncovalent interactions with cationic organic pollutants, thereby promoting effective adsorption. The chemical structure, microstructure, adsorption performance toward organic cationic pollutants, and the underlying adsorption mechanisms of the synthesized ionic hyper-cross-linked polymers were comprehensively investigated. The findings provide valuable insights for the high-value utilization of lignin, expand the molecular design strategies for functionalized ionic hyper-cross-linked polymers, and contribute to their sustainable development.